A person who wears contact lenses is necessarily obliged to store the contact lenses in a safe place, be it during the night, or due to external conditions such as necessitated by the kind of his activities (swimming, surfing, sailing, combat sport), or due to a reduction in the comfort of wearing these lenses. It is also necessary to remove contact lenses due to a deterioration of the optical qualities caused by deposits like microorganisms covering the surface of the contact lens, or due to damages of these surfaces, for cleaning of the lenses. The known storage cases consist of a flat opaque piece formed with recesses for the contact lenses, which recesses can be closed by a threaded cover. Both hydrophilic and gas-permeable lenses should be stored in a humid atmosphere, because a hydrophilic lens may be destroyed when drying, whereas a gas-permeable lens changes its form. Storage in a humid surrounding permits asepsis of the lens due to antiseptic additives in the storage means.
As is well known, contact lenses must be inspected from time to time for deposits, microorganisms, fungi, mechanical damages and changes to to ageing. All these detrimentally influence wearing comfort; they possibly lead to complications on the eye itself.
Inspection of lenses can be carried out by an ophthalmologist or an optician. The necessity of such regular inspections will briefly be referred to in the following paragraphs.
As is known, organic and inorganic deposits are formed on the surfaces of the contact lenses, and microorganisms as well as fungi collect there as well. The inorganic deposits are parts of the lacrimal fluid such as proteins, mucines and lipids. The inorganic deposits (metals, iron, rust) are due to environmental conditions (air pollution, road dust, metal, abrasives). Additional inorganic deposits are those of calcium salts which are also called hard-water deposits. They are formed when flushing the lenses with tap water or due to a change of the pH value of the lacrimal fluid, e.g. due to medicaments or physiological influences. The microorganisms (bacteria, viruses) and fungi belong to the normal microflora of the conjunctiva, the conjunctiva sac and the lacrimal ducts. Changes occur when the balance of the microflora becomes disturbed, be it due to germ transfer via the hands, improper cleaning and desinfection, illness or metabolic disturbances (diabetic) of the lens wearer or due to contact of the lenses with the environment. In addition it is known that the contact lenses, in the course of their use, are subjected to changes, damages and ageing of their material. The changes of the material (e.g. discolorations) can be based on environmental influences (cigarette smoke, color vapors, cosmetics, staining of storage containers) ageing and also on standard cleaning methods. Lens damage (hairline cracks, abrasions, scratches, marginal fractures) are due to improper handling, dissication and cleaning of the lenses. These changes lead to a sequence of complications for the user or wearer. Serious complications with disadvantageous consequences for the eye concerned have already been described. On account of them, each wearer of contact lenses is instructed to periodically have his eyes and lenses inspected. The wearing of contact lenses leads, after a certain time, to troubles in the sensitivity of the cornea. Due to this, the wearer of contact lenses often feel the complications rather late, and valuable time is lost until they contact an ophthalmologist. A device that would enable each wearer to inspect his contact lenses in a simple manner might therefore avoid such complications in many cases.
Several cleaning methods are used. They are not listed here since they are not part of the invention. The inspection of the contact lenses could be effected by the wearer himself if he had a device easy to handle and at a reasonable price at his disposal. However, this self-inspection does not substitute the inspection by the contact lens specialist.